The present invention generally relates to systems and methods for delivering and/or receiving a substance or substances such as blood, from subjects, e.g., from the skin and/or from other tissues of the body. In some cases, the device may contain a substance transfer component such as needles or microneedles, which can be inserted into the skin or another organ to deliver and/or receiving fluid or other substances from the subject. In some embodiments, the device may include an activator constructed and arranged to insert one or more substance transfer components into the skin or other organ. In certain cases, the device may also include a storage chamber for receiving a fluid received from the subject.