In this article, we present an acoustofluidic device with PDMS-embedded IDTs for controlled injection of water-in-oil droplets, operating in the kHz frequency domain and therefore mitigating thermal side-effects in droplet manipulations. We design a one-chip acoustofluidic PDMS-device consisting of curved serpentine-paired channels for embedding liquid metal IDTs with a focusing geometry. The mechanical actuation from our embedded IDTs is pin-pointed to the T-junction of the microfluidic channels where we demonstrate an acoustically-mediated droplet injection strategy that we call acoustoinjection. First, we investigate the working principle underlying acoustoinjection by correlating IDT quality with function. We perform laser doppler vibrometry (LDV) measurements to physically determine the optimal resonant frequencies of our devices and visualize the acoustic field when working under high-or low-frequencies. Using infrared imaging, we highlight minimal thermal contributions when operating the devices at kHz frequencies. It is important to note that the minimal heating of the PDMS slab during device operation is advantageous when considering future applications that require stable conditions for handling complex fluids or biological samples. Finally, we demonstrate controlled acoustoinjection of surfactant stabilized water-inoil droplets with the acoustic field produced by our IDTs. We evaluate different droplet passing rates with variable surfactant concentrations and measure the total amount of injected droplets, finding a high reproducibility and reliability for our devices. Given the simple production, operation, and consistency of our integrated acoustofluidics device, we expect that any lab with microfluidics capabilities could adopt droplet acoustoinjection technology into their toolboxes.